1. Field of the Invention
The present invention relates to an electronic program table processing apparatus for and an electronic program table processing method of obtaining program information superimposed on a broadcasting wave and displaying an electronic program table on a television screen, for example. The present invention further relates to a computer program product to make a computer function as such an apparatus.
2. Description of the Related Art
An electronic program table processing apparatus generates an electronic program table (or electronic program list) of an electronic program guide (EPG) and displays the electronic program table on a screen, so that a user who is a viewer of the television broadcasting obtains a desired program search result accurately and easily.
For example, an electronic program table processing apparatus disclosed in Japanese Patent Application Laid-Open No. 2002-232805 has a setting device which allows the user to select a display mode from among the following program table display modes (a) to (d) according to his/her preference.
That is, they are (a) a first program table display mode in which program table data for five hours relating to the presently selected channel and two channels adjacent to the presently selected channel is generated, and this program table data is updated by a unit of five hours according to a predetermined lapse of time, (b) a second program table display mode in which program table data for three hours relating to the presently selected channel and four channels adjacent to the presently selected channel is generated, and this program table data is updated by a unit of three hours according to a predetermined lapse of time, (c) a third program table display mode in which program table data for one day relating to the presently selected channel is generated, and this program table data is updated by a unit of one day, according to a predetermined lapse of time, and (d) a fourth program table display mode in which program table data for one hour relating to eight to twelve channels is generated, and this program table data is updated by a unit of one hour.
This electronic program table processing apparatus can be considered to be applicable to many users having various demands, since a plurality of program table modes are prepared in advance.
However, the conventional electronic program table processing apparatus and apparatuses analogous to this often have problems as described below.
In digital broadcasting, the number of receivable channels is different among receiving areas. For example, in a town, the number of receivable channels is relatively large. However, in countryside, the number of receivable channels is relatively small. For example, in an area in which the number of receivable channels is extremely small, many nonuse frames (i.e. blank spaces) appear in the displayed electronic program table, resulting in deteriorated display efficiency. The above-mentioned conventional electronic program table processing apparatus has a plurality of program table display modes, and thereby, it can satisfy various demands of users. However, in this apparatus, the number of channels displayable on one screen is fixed in each program table display mode. Add to this, it is actually impossible to prepare program tables for the all areas. For these reasons, there is a technical problem that the display efficiency of the electronic program table may be deteriorated depending on the receiving state of the broadcasting wave (i.e. differences of the number of receivable channels among areas).